Hello,
thank you for looking into this and your answer. Unfortunately the application of 0041-drm-sun4i-dw-hdmi-Switch-to-bridge-functions.patch also leads to no audio over hdmi on my h6mini. Than I tried LibreELEC-H6.aarch64-12.2-nightly-20251216-877c02d-tanix-tx6.img.gz because I thought that I made something wrong with my source, but got also no audio.
I've also have a problem with the media-cedrus-Implement-AFBC-YUV420-formats-for-H265.patch. My eachlink h6 mini does not support 8 Bit media in h265 only 10 Bit media like it is written on https://linux-sunxi.org/Cedrus#Supported_codec_matrix. So I had to remove that mode from cedrus_video.c
Maybe eachlink h6 mini and tanix TX6 differ more than I thought.